Implement retainer



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NW, m; 193?. a. H. FUEHRER IMPLEMENT RETAINER Filed June 26, 1957 'INVENTOR I ,Geoa ellliwimea H IS ATTORN EY.

Patented Nov. 16, 1937 George H. Fuehrer; Phillipsburg,=- N. J}, assignor to Ingersoll-Rand Company-I"Jrsey City, N. J-., a

corporation of New Jersey. 1 Application June 26, 1937, SerialIN'0. 150,519

- 2 'Claims. (Cl.- 121--32)-' This invention relates to rock drills, and more particularly-to an implementretainerfor rock drills ofthe type in which the working, implement, and the percussive element actuating it respond with, thec'urvature of the periphery of' trunnions 35' arranged on opposite sides) of the casing 2| and extending laterally thereof. Ad'- jacent the concave surfaces 34and on thesame are-capable of relative reciprocatory movement. ends .'--of the flanges 29 as the concave surfaces 5 7 It is an objectof this inventionto provide a are fiat surfaces 36 which seat against similar simple and efficient device toretain the working surfaces 3'! on the trunnions 35to prevent moveimplement in; the rockdrill and one that may be m'ent of the yoke 2! beyond the correct retaincheaply manufactured and readily attached ing position,

10 to and removed from the drill. The trunnions 35 are hollow having bores 38 10 Other objects will be in part obvious and in which open from the free ends of the trunnions, part pointed out hereinafter. and in the walls of the trunnions are dia- In the drawing accompanying this specificametrically opposed elongated apertures 39 tion and in which similar reference numeralsreand 4D to receive the bolts 3|. The aperfer to similar parts, tures extend from the bores 38 to the peripheries Figure 1 is an elevation, partly broken away, of the trunnions. They taper outwardly and adof an implement retainer constructed in 'acjacent their outer ends are seating surfaces 4| cordance with the practice of the invention and and 42 which are angularly disposed with rea. rock drill to which it is applied, spect to each other and form seats for washers.v FigureZ isaside elevation, partly broken away, 43 which are held against the seating surfaces 20 taken through Figure ion the line 22, and by nuts 44 threaded on the bolts 3|.

Figure 3.is a transverse View taken through The seating surfaces 4| and 42 lie normal to Figure l on the line 3-.-3 the portions of the apertures 40 which they en- Referring more particularly to the drawing, circle so that in one position of the bolts 3| the the implement retainer, designated in its entirety Washers 43 will seat upon the surface 4| and in 25 r by 20, is shown applied to the front end of a caso er limiting p s p the Su ace 42 ing 2| of a rock drill adapted to actuate a workto hold the yoke against unauthorized movement ing implement 22 which extends into and is with respect to the Working implement 22. guided by a, bushing 23 arranged in the front end In order to assure oscillatory movement of the of the casing 2|. bolts 3| in equal degree and thereby preclude 30 The working implement 22 has a collar 24 distortion of the yoke, bearings 45 in the form which seats against the front end of the bushof plugs are dispos rotatably in he ores 38 ing 23 to limit the distance which the working and have apertures 46 to receive the bolts 4|. implement may extend into the rock drill. The The bearings 45 are freely rotatable in the bores rear or shank end of the Working implement exand serve to maintain the axes of the bolts in 35 tends rearwardly of the bushing 23 and. into a th planes of the axes of t bores- Thus, when cavity 25 in the casing to receive the blows of the yoke 21 is rocked relatively to the trunnions a hammer piston 26 reciprocable in the casing the bolts will be retained in the same plane and 2|. the chances of one side arm 28 being drawn out The implement retainer 20, constructed in acof the plane of the other and a consequent dis-' 0 cordance with the practice of the invention, comtortion of the yoke will, therefore, be obviated. prises a yoke 21 shaped to partly encircle the In assembling the retainer on the rock drill Working implement '22 about which it is disthe bearings are placed in the bores 38 and posed, in the retaining position, forwardly ofthe after the springs have been assembled on the collar 24. The yoke 21 has integral side arms bolts 3| the latter are inserted in the apertures 45 28 which carry at their rearward ends flanges e fla ges 29 and thereafter in the 29 having apertures 30 to accommodate bolts 3| apertures and After the as s 43 upon which the yoke is slidably mounted. The have been placed on the bolts thenuts 44 are head portions 32 of the bolts serve as seats for t r a d in p siti t pa tly pr ss the 50 springs 33 arranged about the bolts and acting sprin s 33 Which, y acting st the heads 32 with their other ends against the forward surand the flanges 29, press the concave surfaces 34 faces of the flanges 29. into firm frictional engagement with the periph In the rearmost extremities of the flanges 29 eries of the trunnions 35. 1 V are concave surfaces 34 to bear against and cor- The pressure of the springs 33 may be con- 55 veniently adjusted in accordance with requirements by the nuts 44 but should be of such value that the retainer will be held firmly in its limiting positions unaffected by the vibration incident to the operation of the rock drill.

In the normal or retaining position of the retainer the yoke 21 encircles the Working implement forwardly of the collar 24 so that whenever the working implement is projected sharply forwardly or during the withdrawal of the working implement from a drill hole the yoke engages the collar and thus assures the retention of the shank end of the working implement in the rock drill. Whenever it is desired to change working implements the yoke is rocked from the retaining position in which the washer 43 seats upon the surface 4| to one in which the washer 43 seats against the surface 42 and where it will be securely held by the pressure of the spring 33. After the exchange of working implements has been effected the yoke is again returned to its original position to act as an abutment for the collar 24.

During the swinging or shifting of the yoke from one limiting position to the other the bolts 3| will be caused-to move in equal degree by the bearings 45 as will also the side arms 28. As a result, the yoke will remain in true parallelism with the collar 24 so that when the working in'1 plement is projected forwardly a wide area of the collar will contact with the yoke, thereby obviating the changes of point contact and localized strain on the yoke,

I claim:

1. In an implement retainer for percussive tools, the combination of a casing and a working implement in the casing, a retainer for retaining the working implement in the casing, hollow trunnions on the casing having diametrically opposed elongated apertures therein, bolts for clamping the retainer against the trunnions and being swingable in the apertures, and means rotatable in the trunnions forming bearings for the bolts.

2. In an implement retainer for percussive tools, the combination of a casing and a Working implement in the casing, a retainer for retaining the working implement in the casing, hollow trunnions on the casing having diametrically opposed elongated apertures therein, bolts in the apertures extending through the retainer, springs on the bolts to press the retainer against the trunnions, and bearing members for the bolts rotatable in the trunnions.

GEORGE H. FUEHRER. 

